* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #212121;
}

input {
  display: none;
}

.on,
.off {
  position: absolute;
  text-align: center;
  text-shadow: inset 1px 1px 1px black;
  width: 100%;
}

.on {
  color: #fff;
  top: 10px;
  transition: all 0.1s;
  font-family: sans-serif;
}

.off {
  color: #636161;
  bottom: 5px;
  transition: all 0.1s;
  transform: scaleY(0.85);
}

.but {
  background-color: #000;
  border-radius: 400px 400px 400px 400px / 400px 400px 300px 300px;
  border-bottom-width: 0px;
  box-shadow: inset 8px 6px 5px -7px rgba(0, 0, 0, 1),
    inset -8px 6px 5px -7px rgba(0, 0, 0, 1),
    inset 0 -3px 2px -2px rgba(200, 200, 200, 0.5),
    0 3px 3px -2px rgba(0, 0, 0, 1),
    inset 0 -230px 60px -200px rgba(255, 255, 255, 0.2),
    inset 0 220px 40px -200px rgba(0, 0, 0, 0.3);
  display: block;
  font-size: 17px;
  height: 60px;
  position: relative;
  transition: all 0.2s;
  width: 40px;
}

.back {
  background-color: #000;
  background-image: -webkit-linear-gradient(
      0deg,
      transparent 30%,
      transparent 65%
    ),
    -webkit-linear-gradient(0deg, rgba(245, 245, 245, 0) 30%, rgba(
            150,
            150,
            150,
            0.1
          )
          50%, rgba(150, 150, 150, 0) 70%);
  border-radius: 115px;
  box-sizing: border-box;
  height: 85px;
  padding: 4px 4px;
  transition: all 0.2s;
  width: 50px;
}

input:checked + .back .on,
input:checked + .back .off {
  text-shadow: inset 1px 1px 1px black;
}

input:checked + .back .on {
  color: rgb(141, 141, 141);
  top: 10px;
  transform: scaleY(0.85);
}

input:checked + .back .off {
  color: #fff;
  bottom: 5px;
  transform: scaleY(1);
}

input:checked + .back .but {
  background: #232323;
  background-image: -webkit-radial-gradient(
    55% 18%,
    circle closest-corner,
    rgba(0, 0, 0, 0.3),
    rgba(0, 0, 0, 0)
  );
  border-radius: 410px 410px 410px 410px / 310px 310px 410px 410px;
  box-shadow: inset 8px -4px 5px -7px rgba(0, 0, 0, 1),
    inset -8px -4px 5px -7px rgba(0, 0, 0, 1),
    0 -3px 8px -4px rgba(250, 250, 250, 0.4),
    inset 0 3px 4px -2px rgba(10, 10, 10, 1),
    inset 0 280px 40px -200px rgba(0, 0, 0, 0.2),
    inset 0 -200px 40px -200px rgba(180, 180, 180, 0.2);
  margin-top: 20px;
}

input:checked + .back {
  background-image: -webkit-linear-gradient(90deg, black 30%, transparent 65%),
    -webkit-linear-gradient(180deg, rgba(250, 250, 250, 0) 0%, rgba(
            250,
            250,
            250,
            0.4
          )
          50%, rgba(150, 150, 150, 0) 100%);
  box-shadow: 28px 28px 28px -28px rgba(0, 0, 0, 0.1),
    -28px 28px 28px -22px rgba(0, 0, 0, 0.1), 0 30px 30px 0px rgba(0, 0, 0, 0.2),
    inset 0 1px 2px 0 rgba(0, 0, 0, 0.6);
  padding: 2px 4px;
}

.l,
.r {
  margin: 0 auto;
  text-align: center;
}

.round,
#onoff,
.back,
.but,
.on,
.off {
  user-select: none;
}
